The enigmatic "linguistic cerebellum": unravelling cerebellar involvement in phonological processing in primary progressive aphasia and non-language disturbed participants.

Phonological processing refers to our ability to recognise, store, recall and produce the sounds in our
language, and is pivotal for our spoken and written language abilities. Recent research is creating a
body of evidence underlining the importance of the highly understudied cerebellum in phonological
processing. Knowledge of how and to which phonological subprocesses specifically the cerebellum
contributes, is lacking. We will demystify the role of the cerebellum by evaluating the effects of
cerebellar neurostimulation on performance on tasks designed to measure phonological subprocesses
in participants. Cerebellar transcranial direct current stimulation (ctDCS) will be applied to
participants with logopenic primary progressive aphasia (LvPPA): a dementia with a specific core
phonological impairment, and to non-language disturbed (NLD) controls. Our doctoral project has
indicated that ctTDCS can lead to improvements on tasks requiring phonological processing, which
we will now take as our primary focus point. This project will investigate: (1) the impact of ctDCS on
phonological subprocess performance in LvPPA and NLD controls, (2) phonological subprocessing
deficits in LvPPA and (3) ctDCS-induced functional connectivity changes between the stimulated
cerebellum and cortical language areas with EEG. As such, we hope to unravel the role of the long
ignored, "linguistic cerebellum" in phonological processing.